It is long known that cyanoacrylate, in vapor form, adheres to fingerprints. Once the vapor cures, the cyanoacrylate forms a white polymer substance that reveals to the fingerprint. This technique is known as developing a latent fingerprint. Although his process produces good results, the present technology for developing latent prints involves a time consuming process that must be performed in closed quarters. Current technology uses sheet packets of thick liquid cyanoacrylate. The cyanoacrylate is spread on sheets of material and then sealed. To use, the packet is opened by pulling the two sheets apart which then exposes the cyanoacrylate to the air. Typically, these sheets are placed in a closed vessel such as a large aquarium with the object to be examined. The cyanoacrylate vapors can then adhere to the object, developing any prints that might be on the object. This process can take up to six hours. One system calls for placing several packets throughout a room and then sealing the room for up to 24 hours to develop any prints that may be inside.
Examples of patents that use this technique can be found in U.S. Pat. Nos. 4,550,041; 4,729,229; 4,260,645, and 4,613,515. As noted above, these devices and methods all suffer from the same drawbacks: they are slow, taking up to several hours to complete the process, and must be used in a closed container.
It is also known that heat accelerates the vaporization of the cyanoacrylate. U.S. Pat. No. 4,719,119 discusses the drawbacks of using heat as it was taught in 1983. Essentially, the heat process uses a laboratory "hot plate" to warm the cyanoacrylate. In use, the opened pouch is placed on the hot plate within a closed container. As the heat is applied, vaporization accelerates. Notwithstanding the safety problems associated with this technique, it still requires that the test be conducted within a closed container such as an aquarium.